This invention is directed to the field of fire suppressant devices, more particularly to an automatic temperature activated device, a manual device, or a combination thereof, where each version has broad and varied application.
The present invention, in a preferred version, relates to a heat responsive fire suppressant device, of the type that may be mounted in a kitchen range hood, along an automotive engine fire wall, or in industrial locations, where fires could erupt suddenly resulting in serious damage, or even injury. Oftentimes such fires can occur when no one is immediately available to use a conventional, hand operated fire extinguisher, or the fire location is not convenient for using such fire extinguisher. In alternate versions, the device may be operated manually, or the device may offer a combination of automatic and manual.
Heat activated fire extinguishers have been proposed which respond automatically to excessive heat to release a pressurized fire retardant agent, where such proposals date back to the 30""s. Hand held fire extinguishers have a number of limitations that are not associated with automatic distinguishers. Most manual extinguishers include either a dry or wet flame retardant chemical compound placed under pressure within a cylindrical canister which includes an opening in a bottom end, a siphon tube connected at one end to the opening and at the opposite end to a valve scaled outlet, an activation device, such as a spring biased hand grip, for opening and closing the valve and a nozzle at the end of a hose which can be used to direct the retardant compound toward a flame to be extinguished.
In operation, to extinguish a fire, a user directs the nozzle end of the hose toward the flame and triggers the hand activation device to open the valve. Where the extinguisher includes a hose, the compound is forced therethrough and out of the nozzle end to extinguish the fire. Usually, because the compound must travel through the hose prior to being discharged, hose length is limited so that activation time is reduced, pressure required to force the compound through the hose is minimal and minimal compound is wasted within the hose.
A number of limitations are inherent with such traditional fire extinguishers. To be effective, pressure must be maintained at a minimum level. Some extinguishers may be equipped with a pressure scale to visually show the pressure level. Further, while these extinguishers can put out relatively small fires efficiently, assuming the fire is known to the occupant, these extinguishers are typically not suitable for extinguishing larger fires. However, one must be close to the fire, and such close proximity can be a hazard to the user.
Certain of these disadvantages can be overcome by the use of automatic, heat responsive extinguishers which are strategically placed in areas for potential fire hazards, such as kitchen hoods in homes and restaurants, engines of automobiles and other vehicles, and in industrial applications. The prior art teaches several devices for the automatic operation of a fire suppressing system, where such prior art is reflected in the following U.S. Patents:
a.) U.S. Pat. No. 6,003,609, to Walls, relates to a fire safety device for controlling the spread of fire in a structure. The device comprises a base plate, a smoke detector, a syringe, and a cover. The syringe has a reservoir containing a fire retardant chemical. A fuse link holder has a melting fuse link that maintains a plunger assembly in position, and a spring is loaded behind the plunger. The syringe also has a nozzle in open communication with a supply line, which is in open communication to the reservoir. When a sufficiently high ambient temperature is reached, the fuse link melts, releasing the piston rod from the fuse link and allowing the coil spring to urge the plunger toward the other end of the syringe, and forcing the fire-retardant chemical from the nozzle.
b.) U.S. Pat. No. 5,992,531, to Mikulec, teaches a fire extinguisher including a spring biased plunger controlled by a trigger mechanism. The plunger is mounted in a flame retardant compound container and the spring and plunger cooperate, when the trigger mechanism is activated, to discharge flame retardant compound from the container toward a fire. The extinguisher has a handle end and an outlet end at opposite ends of its length such that a user can hold the outlet end in a remote location away from the user when compound is discharged. The extinguisher can also be mounted and provided with a heat sensor for automatic activation.
c.) U.S. Pat. No. 4,088,192, to Lamond, is directed to a heat actuated valve comprising a base adapted to be mounted on a fire extinguisher container. The base includes a passage communicable with the container interior. A pair of stop fingers extend forwardly from the base. A fusible element interconnects the stop fingers. The base, stop fingers and fusible element are of one-piece, integral construction. A plunger is slidably mounted in the passage and includes a passage-blocking portion which blocks the passage when the plunger abuts the stop fingers during a fire sensing mode of operation. The plunger is slidable rearwardly to shift the passage-blocking portion to a first passage-opening position to allow the container to be filled. The plunger is operable, in response to melting of the fuse, to spread the stop fingers apart and travel forwardly sufficiently to shift the passage-blocking portion to a second passage-opening position, enabling the container contents to be discharged.
While the above prior art, and other known devices, propose solutions to the general subject of automatic, heat activated fire suppressing devices, none offer the simplicity, reliability and fast response of preferred the heat activated fire suppressant device of this invention. Further, these prior art designs significantly limit the location and environment for effective operation. The manner by which the present invention achieves these features will become more apparent to those skilled in the art from the description which follows.
This invention preferably relates to a temperature activated fire suppressing device having particular utility in applications where unattended or unexpected fires may erupt. The device, in a preferred embodiment, comprises a cylindrical canister housing, having a uniform bore, and mounting a removable end cap containing a fluid exiting conduit leading to a nozzle mechanism. Alternately, the housing may have different shapes so long as it exhibits a uniform bore throughout. Movable within the cylindrical or different shaped housing is a piston member, cylindrical or comparable shaped to the housing, and axially slidably therewithin, where the piston member is in sealing contact with the inner wall of the housing. The piston member is movable from a first position to a second position by a pressurized fire suppressant fluid in combination with an energy means, where said energy means may be selected from the group consisting of (a) at least one elastic member extending between the end cap and the piston member, and (b) a coil spring positioned behind the piston member. The nozzle mechanism comprises a nozzle opening in communication with the fluid exiting conduit, and a closed cover member. Further, there is a biasing spring acting between said cover member and said nozzle opening to facilitate its removal from the nozzle opening. The closed cover member is temporarily secured to the nozzle opening by a low temperature melting point solder. By this arrangement, when the device is exposed to a fire having a temperature in excess of said low temperature melting point, the solder melts, and with the force of the biasing spring the closed cover member is released from the nozzle opening. With the nozzle opening in communication with the fire suppressant fluid, the fluid is released to act on the fire and is forced out of the device by the release of the stored energy of the energy means. During this releasing action, the piston member is caused to move from said second position to said first position.
Accordingly, an object of a preferred embodiment of this invention is to provide a convenient and reliable fire suppressing device that is activated by exposure to heat.
Another object of the preferred embodiment lies in the use of a heat activated cover member that includes a compressed coil spring to facilitate its separation from the fluid transmission nozzle.
A further object of the invention is a fire suppressing device that can be converted to a manually operated device.
Still a further object hereof is the provision of piston member in fluid sealing and sliding relationship to the inner wall of the cylindrical or different shaped canister housing.
These and other objects will become more apparent from the specification which follows particularly when read by those skilled in the art.